1. Field of the Invention
The present invention relates to an image forming apparatus that includes an image scanner, and an image forming method that is executed by the image forming apparatus.
2. Description of the Related Art
In an image forming apparatus disclosed in Japanese Patent Application Laid-open No. 2005-348435, local characteristics of an input image data are detected and selection data is output. Further, the input image data is separated into two pieces of image data by using the selection data and the most suitable conversion process is carried out respectively for the two pieces of image data and the selection data. Thus, deterioration of image quality can be suppressed and a data amount can be reduced even though various images such as picture photographic images and characters, drawing images are mixed together.
In an image forming apparatus disclosed in Japanese Patent Application Laid-open No. 2004-214949, a compression format of an image data having an obscure compression format is detected. When the compression format is the same as that is used for data processing, the compressed image data is input into a data processor without expanding. Thus, drop in the data processing speed can be prevented.
However, in the technology disclosed in Japanese Patent Application Laid-open No. 2005-348435, because local characteristics of the input image data are detected and processing method is changed accordingly, a separate processor is required for each image data, thus resulting in an excessively big device structure.
Even in the technology disclosed in Japanese Patent Application Laid-open No. 2004-214949, because the image data having a different compression format is sent from one scanner and an image data signal itself is different, a separate processor is required for each image data, thus resulting in the excessively big device structure.